A Program Project is proposed that involves six investigators whose research activities include a broad range of neuroplastic phenomena. These investigators, all members of the Neuroscience Program at the University of Virginia, have well-developed independent research programs, each involving the long-term exploration of a specific vertebrate model system for a particular neuroplastic phenomenon. The proposed Program Project would establish a more formal integration of these research programs with a view toward gaining benefits such as (a) achievement of a better understanding of neuronal modifiability by studying a range of neuroplastic phenomena rather than focussing on a single phenomenon, (b) establishing a foundation for studying different neuroplastic phenomena in the same model systems, (c) sharing of conceptual and technical expertise, (d) joint technique development, (e) establishment of common research support facilities, and (f) building a neuroplasticity program that can serve as a basic science foundation for a developing trauma program. Six projects are proposed involving various collaborative combinations. These include studies of the plasticity of sensory pathways during learning (Project 1), development of central visual pathways and the effects of deprivation (Project 2), pre and postsynaptic control of collateral sprouting induced by injury (Project 3), the role of afferents in regulating dendritic structure and function (Project 4), effects of afferent activity on developing neuronal connectivity (Project 5), and metabolic mapping studies of neuronal plasticity using 2-deoxy glucose uptake (Project 6). In addition, it is proposed to develop histologic-photographic, electronic, and computer programming core facilities for common research support of this neuroplasticity program.